How to handle events about document created/updated

I would like to use ES as primary data storage. I want to receive PUT request in ES, handle event using some listener and than store data asynchronously into other data storage (Postgres database for example). Is it possible to implement using existing extensions?

Previously, I read topics
http://elasticsearch-users.115913.n3.nabble.com/Using-ES-as-our-primary-and-only-datastore-td3100393.html
and
http://groups.google.com/a/elasticsearch.com/group/users/browse_thread/thread/f8ff072a7039292d/f90501e0861b4e99#f90501e0861b4e99

I understand that it is impossible to use ES as single data-storage. By this I decided to use a different database to store data backup and some backdoor functionality.

Thanks!
Best regards, Vitalii Siryi